The main issues with the Apple Mac OS Catalina:

• Problem with the Catalina update on macOS -The following macOS Catalina update issues are possible: This page could not be found. During the installation of the selected updates, an error occurred. The 'Setting Up Your Mac...' screen is stalled during installation. The macOS operating system could not be installed on your computer. There is insufficient free space on the Macintosh HD for installation. Restart your computer and try again after quitting the installer.
• Mac Slowdown or Overheating Issue: macOS Catalina causes your Mac to slow down or overheat. On macOS Catalina, Activity Monitor shows a lot of CPU utilisation.
• Problem with 32-Bit Apps in macOS Catalina Problem: 32-bit apps do not operate in macOS Catalina.
• The following macOS Catalina email issues are possible :Mail app crashes in macOS Catalina. Some emails are lost after the macOS Catalina upgrade. The search function doesn’t work in the Mail app.

Read More: Will Mac OS Catalina make my Mac faster?